Wafer cassette

1. A wafer cassette for storing a plurality of wafer-shaped substrates, comprising: a case body, the case body having a gate through which the wafer-shaped substrates are loaded into or unloaded from the case body; at least one fitting portion located in the case body; and an adapter comprising a plurality of support portions individually supporting the wafer-shaped substrates so that the end portions of wafer-shaped substrates of different sizes are situated in the same predetermined position at the gate of the case body, and at least one fittable portion removably attached to the case body in the at least one fitting portion.

2. A wafer cassette according to claim 1 , wherein the adapter includes a pair of adapter elements, each of the adapter elements having a plurality of support portions individually supporting the wafer-shaped substrates.

3. A wafer cassette according to claim 1 , wherein the adapter supports the wafer-shaped substrates, one at a time.

4. A wafer cassette according to claim 3 , wherein the at least one fitting portion or the fittable portion of the adapter is a projection, and the other is a fitting hole in which the projection is fitted.

5. A wafer cassette according to claim 1 , wherein the adapter is of one of a plurality of types having the support portions different in construction, the construction of each type corresponding to the size of the wafer-shaped substrates to be supported, and the case body can be loaded with adapters of at least two types.

6. A wafer cassette according to claim 5 , wherein the adapter supports a plurality of wafer-shaped substrates of the same size.

7. A wafer cassette according to claim 5 , wherein the adapter supports a plurality of wafer-shaped substrates of different sizes.

8. A wafer cassette according to claim 5 , wherein each said support portion of the adapter has a projection for preventing the supported wafer-shaped substrates from springing out.